J-amino-x-cyanopyrazole and method



"ilnitc S-AMINO-l-CYANOPYRAZOLE OF PREPARING George H. Hitchings, Tuckahoe, and Elvira A. Falco, New Rochelle, N. Y., assignors to Burroughs Wellcome & Co. (U. S. A.) Inc., Tuckahoe, N. Y., a corporation of New York No Drawing. Application October 27, 1955, Serial No. 543,246

2 Claims. (Cl. 260-310) AND METHOD The present invention relates to a new compound 3-amino-4-cyanopyrazole, which is a useful and valuable intermediate in the preparation of new pyrazoles and also for the manufacture of the important pyrazolo (3,4-d) pyrimidines. Pyrazolopyrimidines are inhibitors of cell division, probably as purine antagonists. These pyrazolopyrimidines no cyano pyrazole thiourea or formamide in accord with the following re HgN States Patent Ofifice 2,759,949 Patented Aug. 21, 1956 Formamide In accordance with the invention, the new compound the reaction of ethoxy- The aminocyanopyrazole, so formed, can be used as an intermediate for the synthesis of pyrazoles, and, by reaction with reagents such as formamide and urea, of various pyrazolo (3,4-d) pyrimidines.

Method of preparation A. Ethoxymethylene malonom'trile (5 g.) and hydrazine 5.2 g. were mixed. After the addition of ml. of absolute ethanol, the solution was heated on the steam bath for one hour and evaporated to dryness. The residue was extracted with alcohol and recrystallized from hot water.

B. Ethoxymethylene malononitrile drazine 5.2 g. were mixed as before, added, and the mixture heated under overnight. The product was worked after recrystallization, melted at 172.

C. Ethoxymethylene malononitrile (20 g.) was added in portions to 15 ml. of hydrazine hydrate in water. After the addition of ml. of ethanol, the mix ture was heated for two hours on the steam bath and then evaporated to dryness. The residue was extracted with cold water, and the solid was then recrystallized from hot water.

What we claim is:

1. As a new compound, 3-amino-4-cyanopyrazole.

2. The method of making 3-amino-4-cyanopyrazole which comprises reacting ethoxymethylene malononitrile with hydrazine.

(20 g.) and hy- 50 ml. of ethanol a reflux condenser up as before, and

No references cited. 

1. AS A NEW COMPOUND, 3-AMINO-4-CYANOPYRAZOLE. 